1. Field of the Invention
This invention relates to a memory card reading/writing apparatus that access information stored on a removable memory card, and more particularly to a memory card reading/writing apparatus that has a function for determining the owner of the memory card.
2. Description of the Related Art
In recent years, as semiconductor memories have been made more compact and mobile, and their capacity increased, memory cards have become known as a compact memory medium that can be conveniently carried and can store all kinds of data such as text files, audio contents, video contents and the like. Moreover, by taking advantage of their feature of being small in size, the memory cards can be installed in portable devices such as audio players, digital still cameras, PDAs (Personal Digital Assistants), etc. For example, an SD (Secure Digital) memory card is well known as this type of memory card.
Currently, this kind of memory card is relatively expensive, so the owner (user) does not normally transfer or distribute their memory cards to others.
It can be expected that memory cards will become less expensive in the future. That is apparent when looking at other widely used media such as FDs (Floppy Disks (R)) or CD-R.
In that kind of situation, memory cards could easily transferred to others, or it is feasible that they could be shared among a specific group. For example, memory cards could be used for neighborhood bulletins that are circulated among members of the neighborhood, or in an ‘exchange-diary’ that is kept among friends.
Also, depending on the type of recorded data, for example audio data, video data, text files or the like, it is also conceivable that one person may have a plurality of memory cards.
However, in the case of use where the memory card is transferred to other people or shard among a specific group, with the security technology that is used for current memory cards or other recording media, there is a possibility of obstacles to the type of use mentioned above.
In other words, the following problems would occur when absolutely no security was performed when using the memory card. For example, in the case when there are data stored in an exchange-diary or the like that are not to be seen by others, the user or group do not think favorably about others being able to see that data. That is, in the case that a memory card on which this kind of data are stored is lost, when there is no security performed, the uneasiness felt by the user is greater than in the case when security is performed.
On the other hand, in the case when stringent security is performed when using the memory card, a method for clearing the security performance, such as a password, must be given to all users. In other words, in the case of many users sharing a memory card, with the aforementioned stringent security, complicated operations are needed in order to reference the data.
An example of this stringent security is disclosed in Japanese laid-open publication No. 2001-211170. In this art, by performing an identification process that uses ID data for the memory card and ID data for the device, it is possible to prevent the memory card from being used by a device other than a specified device.
However, in this prior art, it is necessary to equip the memory card with a specific security function, and this is not possible for memory cards that are not equipped with the security function that is available in the current market. Also, as described above, the memory card can only be used on a specified device that is equipped with this kind of stringent security function, so this art cannot be used in the case when the memory card is shared by a plurality of uses.
In other words, this does not mean that security is not necessary for data that are stored on the memory card shared by a plurality of users, however, in the case of setting stringent security, there is the tendency for use to be hindered.
Moreover, in the case of a plurality of owned memory cards, a problem of managing the memory cards also occurs in addition to the problem of security described above. In other words one problem is related to managing the memory cards themselves.
As a method for managing the memory cards themselves, it is possible to attach a label to the memory card on which the contents of the various kinds of stored data are described, similar to the case of a conventional FD (R). However, since memory card continue to be made more and more compact, it is difficult to attach a label to a memory card giving the owner's name and description of the contents. Also, in the case of a person having a plurality of memory cards, attaching a label to each memory card is not only troublesome, but there is also a possibility that the label could be pared off when inserting or removing the memory card from the memory card reading/writing apparatus.
Moreover, a problem of managing the data stored on the memory card also occurs. In other words, when various kinds of data are stored on a memory card, it is necessary to execute a special application or use a special device for each kind of data in order to identify the contents of the memory card. Here, it is possible to use file-management software on a personal computer to identify the file names, however, identifying the titles of songs in the case of audio contents, for example, is not easy with a special kind of contents-management method of the memory card. In other words, a problem exists in that it is not easy to identify the contents of the data stored on the memory card.
Furthermore, a problem related to management of the users of the memory card occurs. That is, in a situation where a plurality of memory cards is shared by a plurality of users, there is a problem in that it is difficult to know who the main owner of the memory card is.